Which nerve passes through the carpal tunnel?

• A. Ulnar nerve
• B. Radial nerve
• C. Median nerve
• D. Axillary nerve

Answer: (C)

The carpal tunnel is a narrow passage on the palm side of the wrist formed by the carpal bones and the flexor retinaculum, and it contains the tendons of the flexor muscles plus the median nerve. The nerve that travels through this tunnel is the median nerve, which provides sensation to the lateral three and a half digits and motor control to the thenar muscles and the lateral two lumbricals. If this tunnel narrows or becomes inflamed, the median nerve can be compressed, leading to symptoms like numbness, tingling, and weakness in those areas.

The other nerves don’t pass through the carpal tunnel. The ulnar nerve travels through Guyon’s canal at the wrist and mainly supplies sensation to the medial one and a half digits and most intrinsic hand muscles. The radial nerve does not pass through the carpal tunnel; its forearm and hand branches are distributed differently. The axillary nerve is involved with the shoulder region around the glenohumeral joint, not the wrist.